Non-aqueous electrolytic rechargeable batteries for extended temperature range operation

ABSTRACT

A rechargeable battery is designed with cells having a specific combination of anode, cathode, and electrolyte compositions to maintain long cycle life at extreme high temperatures and deliver high power at extreme low temperatures. These properties can significantly reduce or altogether eliminate the need for thermal management circuitry, reducing weight and cost. Applications in telecommunications backup, transportation, and military defense are contemplated.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 14/536,522, filed on Jul. 11, 2014, which is acontinuation-in-part of International Patent Application No.PCT/US2013/045513, filed on Jun. 12, 2013, which claims priority fromU.S. Provisional Application Ser. Nos. 61/658,712 and 61/658,704,concurrently filed on Jun. 12, 2012, which are hereby incorporated byreference for all purposes.

TECHNICAL FIELD

This technology relates generally to non-aqueous electrolyticrechargeable batteries with excellent low-temperature characteristics,long-term stability and high energy density.

BACKGROUND

Rechargeable batteries are typically designed to deliver optimalperformance at or close to room temperature. Extreme low or hightemperatures can compromise the performance and/or life of the battery.As a result, heating or cooling systems must be integrated toeffectively utilize batteries in these operating conditions, which addscomplexity and cost. In many cases, this inhibits the deployment ofadvanced batteries for applications in extreme temperature environments.

SUMMARY

A rechargeable battery is designed with cells having a specificcombination of anode, cathode, and electrolyte compositions to maintainlong cycle life at extreme high temperatures and deliver high power atextreme low temperatures. These properties can significantly reduce oraltogether eliminate the need for thermal management circuitry, reducingweight and cost Applications in telecommunications backup,transportation, and military defense are contemplated.

In one aspect, a rechargeable battery includes a carbon-containingnegative electrode capable of intercalating and liberating lithium, apositive electrode comprising a lithium transition metal oxoanionelectroactive material, a separator; and a nonaqueous electrolytesolution comprising a lithium salt and at least one organic solvent,wherein the nonaqueous electrolytic solution is free of γ-butyrolactoneand the organic solvent comprises vinylene carbonate, the at least oneadditive represented by the formula (1):

R₁-A-R₂

in which, R1 and R2 independently represent an alkyl group which may besubstituted with an aryl group or halogen atom; an aryl group which maybe substituted with an alkyl group or halogen atom; or may be takentogether to form, together with -A-, a cyclic structure which maycontain an unsaturated bond, where “A” is represented by a formulaselected from the group consisting of

In one or more embodiments, the electrolytic solution contains 0.1 to 5weight % of the compound represented by formula (1).

In one or more embodiments, the electrolytic solution contains 1 to 3weight % of the compound represented by formula (1).

In one or more embodiments, the electrolytic solution contains 1 to 1-5weight % of the compound represented by formula (1).

In one or more embodiments, the electrolytic solution contains 0.2 to 8vol % vinylene carbonate.

In one or more embodiments, the electrolytic solution contains 0.5 to 3vol % vinylene carbonate.

In one or more embodiments, the electrolytic solution contains 0.5 to 2vol % vinylene carbonate.

In one or more embodiments, the compound represented by formula (1)comprises ethylene sulfite.

In one or more embodiments, the negative electrode comprisescarbonaceous materials.

In one or more embodiments, the negative electrode comprisesnon-graphitizable carbon, artificial graphite and natural graphitecombinations of carbonaceous materials with silicon or silicon oxide.

In one or more embodiments, the lithium transition metal oxoanionmaterial is selected from the group consisting of:

-   -   a composition Li_(x)(M′_(1-a)M″_(a))_(y)(XO₄)_(z),        Li_(x)(M′_(1-a)M″_(a))y(OXO₄)_(z), or        Li_(x)(M′_(1-a)M₁″_(a))_(y)(X₂O₇)_(z), having a conductivity at        27° C. of at least about 10⁻⁸ S/cm, wherein M′ is a first-row        transition metal, X is at least one of phosphorus, sulfur,        arsenic, boron, aluminum, silicon, vanadium, molybdenum and        tungsten, M″ is one or more Group IIA, IIIA, IVA, VA, VIA, VIIA,        VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, 0.0001<a≦0.1, and        x, y, and z are greater than 0 and have values such that x, plus        y(1-a) times the formal valence or valences of M′ plus ya times        the formal valence or valences of M″ is equal to z times the        formal valence of the XO₄, X₂O₇ or OXO₄ group;    -   a composition (Li_(1-a)M″_(a))_(x)M′_(y)(XO₄)_(z),        (Li_(1-a)M″_(a))_(x)M′_(y)(OXO₄)_(z), or        (Li_(1-a)M″_(a))_(x)M′_(y)(X₂O₇)_(z), having a conductivity at        27° C. of at least about 10⁻⁸ S/cm, wherein M is a first-row        transition metal, X is at least one of phosphorus, sulfur,        arsenic, boron, aluminum, silicon, vanadium, molybdenum and        tungsten, M″ any of a Group IIA, IIIA, IVA, VA, VIA, VIIA,        VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, 0.0001<a≦0.1, and        x, y and z are greater than 0 and have values such that (1-a)x        plus the quantity ax time the formal valence or valences of M″        plus y times the formal valence or valences of M′ is equal to z        times the formal valence of the XO₄, X₂O₇ or OXO₄ group; and    -   a composition (Li_(b-a)M″_(a))_(x)M′_(y)(XO₄)_(z),        (Li_(b-a)M″_(a))_(x)M′_(y)(OXO₄)_(z), or        (Li_(b-a)M″_(a))_(x)M′_(y)(O₂D₇)_(z), having a conductivity at        27° C. of at least about 10⁻⁸ S/cm, wherein M′ is a first-row        transition metal, X is at least one of phosphorus, sulfur,        arsenic, boron, aluminum, silicon, vanadium, molybdenum and        tungsten, M″ any of a Group IIA, IIIA, IVA, VA, VIA, VIIA,        VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D is oxygen,        0.0001<a≦0.1, a≦b≦1, and x, y, and z are greater than 0 and have        values such that, (b-a)x plus the quantity ax times the formal        valence or valences of M″ plus y times the formal valence or        valences of M′ is equal to z times the formal valence of the        XO₄, X₂O₇ or OXO₄ group.

In one or more embodiments, the lithium transition metal oxoanionmaterial is a lithium transition metal phosphate compound having theformula selected from the group consisting of:

-   -   (a) (Li_(1-x)Z_(x))MPO₄, where M is one or more of vanadium,        chromium, manganese, iron, cobalt and nickel, Z is one or more        of titanium, zirconium, niobium, aluminum, tantalum, tungsten or        magnesium, and x ranges from 0 to 0.05; and    -   (b) Li_(1-x)MPO₄, wherein M is selected from the group        consisting of vanadium, chromium, manganese, iron, cobalt and        nickel; and 0≦x≦1.

In one or more embodiments, where said positive electrode has a specificsurface area of at least 5 m²/g.

In one or more embodiments, the positive electrode comprises oliviniclithium iron phosphate, optionally containing one or more additionalmetals.

In one or more embodiments, the battery comprises a solid electrolyteinterface (SEI) layer at the anode and the SEI layer comprises areaction product that is the result of a reaction of thecarbon-containing negative electrode and the additive represented by theformula (1).

In one or more embodiments, the area specific impedance at the anode isless than the impedance at an anode in a cell lacking the additiverepresented by the formula (1).

In one or more embodiments, the molar concentration of the lithium saltis between 0.5 and 2.0 mol/l.

In one or more embodiments, the lithium salt is selected from the groupconsisting of LiClO₄, LiPF₆, LiBF₄, LiCF₃ SO₃, LiN(CF₃SO₂)₂,LiN(CF₃CF₂SO₂)₂, LiN(CF₃SO₂)(C₄F₉SO₂) and LiC(CF₃SO₂)₃.

In one or more embodiments, the electrolytic solution further comprisesaprotic solvents.

In one or more embodiments, the solvent comprises at least one ofethylene carbonate, propylene carbonate, butylene carbonate, dimethylcarbonate, diethyl carbonate and ethyl methyl carbonate,γ-valerolactone, methyl acetate, methyl propionate, tetrahydrofuran,2-methyl tetrahydrofuran, tetrahydropyran, dimethoxyethane,dimethoxymethane, ethylene methyl phosphate, ethyl ethylene phosphate,trimethyl phosphate, triethyl phosphate, halides thereof vinyl ethylenecarbonate and fluoroethylenecarbonate, poly(ethylene glycol),diacrylate, and combinations thereof.

In one or more embodiments, the electrolytic solution comprises amixture of ethylene carbonate, propylene carbonate, ethylmethylcarbonate, and diethyl carbonate.

In one or more embodiments, the battery is contained within a pouch.

In another aspect, a battery system includes a plurality of rechargeablebatteries of the preceding embodiments.

In one or more embodiments, the plurality of rechargeable batteries isconfigured to provide an operating voltage of about 12 volts.

In one or more embodiments, the battery is capable of operating within−30° C. to +70° C. without battery management circuitry.

In one or more embodiments, the battery system includes 4 to 16 cellswith cathodes comprising lithium iron phosphate.

In another aspect, a microhybrid battery includes a battery housing; aplurality of rechargeable batteries within the battery housing, whereinthe rechargeable battery includes any of the preceding embodiments; anda cut-off switch for making and breaking a conductive path between theplurality of rechargeable batteries and an external contact.

In one or more embodiments, the plurality of rechargeable batteries areconfigured to provide an operating voltage of about 12 volts.

In one or more embodiments, the battery is capable of operating within−30° C. to +70° C. without battery management circuitry.

In one or more embodiments, the battery capacity decreases less than 10%after 300 charge-discharge cycles at 75° C. with 100% depth of dischargeand at least 1 C charge rate.

In one or more embodiments, the battery can draw at least 20% morecurrent at −30° C. than a battery comprising rechargeable batterieslacking the additive represented by formula (1).

In another aspect, a nonaqueous electrolyte solution includes a lithiumsalt; and at least one organic solvent, wherein the nonaqueouselectrolytic solution is free of γ-butyrolactone and the organic solventcomprises vinylene carbonate, and at least one additive represented bythe formula (1):

R₁-A-R₂

in which R₁ and R₂ independently represent an alkyl group which may besubstituted with an aryl group or halogen atom; an aryl group which maybe substituted with an alkyl group or halogen atom; or may be takentogether to form, together with -A-, a cyclic structure which maycontain an unsaturated bond, where “A” is represented by a formulaselected from the group consisting of

In one or more embodiments, the electrolytic solution contains 0.1 to 5weight % of the compound represented by formula (1).

In one or more embodiments, the electrolytic solution contains 0.1 to 3weight % of the compound represented by formula (1).

In one or more embodiments, the electrolytic solution contains 1 to 1.5weight % of the compound represented by formula (1).

In one or more embodiments, the electrolytic solution contains 0.2 to 8vol % of vinylene carbonate.

In one or more embodiments, the electrolytic solution contains 0.5 to 3vol % of vinylene carbonate.

In one or more embodiments, the electrolytic solution contains 0.5 to 2vol % of vinylene carbonate.

In one or more embodiments, the compound represented by formula (1)comprises ethylene sulfite.

In one or more embodiments, the electrolytic solution further comprisesaprotic solvents.

In one or more embodiments, the solvent comprises at least one ofethylene carbonate, propylene carbonate, butylene carbonate, dimethylcarbonate, diethyl carbonate and ethyl methyl carbonate,γ-valerolactone, methyl acetate, methyl propionate, tetrahydrofuran,2-methyl tetrahydrofuran, tetrahydropyran, dimethoxyethane,dimethoxymethane, ethylene methyl phosphate, ethyl ethylene phosphate,trimethyl phosphate, triethyl phosphate, halides thereof, vinyl ethylenecarbonate and fluoroethylenecarbonate, poly(ethylene glycol),diacrylate, and combinations thereof.

In one or more embodiments, the electrolytic solution comprises amixture of ethylene carbonate, propylene carbonate, ethylmethylcarbonate, and diethyl carbonate.

These and other aspects and embodiments of the disclosure areillustrated and described below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described with reference to the following figures,which are presented for the purpose of illustration only and are notintended to be limiting. In the Drawings:

FIG. 1 is a schematic illustration of an exemplary microhybrid battery,according to one or more embodiments. Inset is a photograph of anexemplary battery.

FIG. 2 is a plot of an anode half-cell's formation curve with only ESadditive in the electrolyte, according to one or more embodiments.

FIG. 3 is a plot of the formation curves for a single use of twosecondary cells, one with only ES additive in the electrolyte, and onewith ES and VC, according to one or more embodiments.

FIG. 4A-B are two plots of the cold cranking current capability of threedifferent 60 Ah (A) and 80 Ah (B) capacity batteries: a lead add AGMbattery, a control lithium metal phosphate battery, and a lithium metalphosphate battery with a modified electrolyte composition, according toone or more embodiments.

FIG. 5A-B are two plots comparing the capacity loss for two 6 Ah (A) and20 Ah (B) capacity batteries at 55° C.: a control lithium metalphosphate battery and a lithium metal phosphate battery with a modifiedelectrolyte composition, according to one or more embodiments.

FIG. 6A-B are two plots comparing the power loss for two 6 Ah (A) and 20Ah (B) capacity batteries at 55° C.: a control lithium metal phosphatebattery and a lithium metal phosphate battery with a modifiedelectrolyte composition, according to one or more embodiments.

FIG. 7A-B are two plots comparing the capacity loss at 45° C. for 5000(A) and 1800 (B) cycles of a lithium metal phosphate battery with amodified electrolyte composition and leading competitor batteries.

FIG. 8A-B are two plots comparing the capacity loss at 60° C. (A) and75° C. (B) of a lithium metal phosphate battery with a modifiedelectrolyte composition and leading competitor batteries.

FIG. 9 is a plot of relative DC resistance changes versus cycle numbersfor two PHEV 20 Ah cells: a control lithium metal phosphate battery anda lithium metal phosphate battery with a modified electrolytecomposition, according to one or more embodiments.

DETAILED DESCRIPTION

Standard lithium ion technology provides relatively low power at lowtemperatures. Additionally, designs fix increasing power at lowtemperature often result in short life at high temperature. As detailedbelow, this often occurs because modifications of the electrolyte thatlower its impedance at low temperatures (0 to −30° C.), for increasedpower, tends to render the solid electrolyte interface (SEI) to be lessstable at high temperatures (room temperature to 75° C.). This hastraditionally inhibited their use for applications in extremetemperature environments.

In one embodiment, an electrolyte composition is provided that enhanceselectrochemical and thermal stability over a wide range of temperatureswhen used in a lithium ion battery.

The rechargeable batteries containing cells with the anode, cathode, andelectrolyte compositions as disclosed herein have been found to maintainlong cycle life at extreme high temperatures and deliver high power atextreme low temperatures.

The rechargeable battery contains a negative electrode capable ofintercalating and releasing lithium (e.g., a graphitic orsilicon/graphite anode), a positive electrode containing a lithiumtransition metal oxoanion electroactive material, a separator, and anonaqueous electrolytic solution consisting of a lithium salt and atleast one organic solvent, wherein the nonaqueous electrolytic solutionis free of γ-butyrolactone and the organic solvent comprises vinylenecarbonate and at least one additive represented by the formula (1):

R₁-A-R₂   (1)

in which, R1 and R2 independently represent an alkyl group which may besubstituted with an aryl group or halogen atom; an aryl group which maybe substituted with an alkyl group or halogen atom: or may be takentogether to form, together with -A-, a cyclic structure which maycontain an unsaturated bond, where “A” is represented by a formulaselected from the group consisting of

R₁ or R₂ can be an alkyl group preferably having 1 to 4 carbon atoms,which are specifically exemplified as a methyl group, ethyl group,propyl group, isopropyl group and butyl group. Examples of an aryl groupcapable of substituting the alkyl group include phenyl group, naphthylgroup and anthranyl group, among these phenyl group being morepreferable. Preferable examples of a halogen atom capable ofsubstituting the alkyl group include fluorine atom, chlorine atom andbromine atom. A plurality of these substituents may substitute the alkylgroup, and a concomitant substitution by an aryl group and halogen groupis also allowable.

The cyclic structure formed by R₁ and R₂ bound with each other andtogether with -A- is of four-membered or larger ring, and may contain adouble bond or triple bond. Examples of bound group formed by R₁ and R₂bound with each other include —CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—,—CH₂CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂CH₂—, —CH═CH—, —CH═CHCH₂—, —CH═CHCH₂—,—CH₂CH═CHCH₂— and —CH₂CH₂C≡CCH₂CH₂—. One or more hydrogen atoms in thesegroups may be substituted by alkyl group(s), halogen atom(s) arylgroup(s) and so forth.

Specific examples of the compound having “A” as represented by theformula (2) include linear sulfites such as dimethyl sulfite, diethylsulfite, ethyl methyl sulfite, methyl propyl sulfite, ethyl propylsulfite, diphenyl sulfite, methyl phenyl sulfite, ethyl sulfite,dibenzyl sulfite, benzyl methyl sulfite and benzyl ethyl sulfite; cyclicsulfites such as ethylene sulfite, propylene sulfite, butylene sulfite,vinylene sulfite, phenylethylene sulfite, 1-methyl-2-phenylethylenesulfite and 1-ethyl-2-phenylethylene sulfite; and halides of such linearand cyclic sulfites.

Specific examples of the compound having “A” as represented by theformula (3) include linear sulfones such as dimethyl sulfone, diethylsulfone, ethyl methyl sulfone, methyl propyl sulfone, ethyl propylsulfone, diphenyl sulfone, methyl phenyl sulfone, ethyl phenyl sulfone,dibenzyl sulfone, benzyl methyl sulfone and benzyl ethyl sulfone; cyclicsulfones such as sulfolane, 2-methyl sulfolane, 3-methyl sulfolane,2-ethyl sulfolane, 3-ethyl sulfolane, 2,4-dimethyl sulfolane, sulfolane,3-methyl sulfolane, 2-phenyl sulfolane and 3-phenyl sulfolane; andhalides of such linear and cyclic sulfones.

Specific examples of the compound having “A” as represented by theformula (4) include linear sulfonic acid esters such as methylmethanesulfonate, ethyl methanesulfonate, propyl methanesulfonate,methyl ethanesulfonate, ethyl ethanesulfonate, propyl ethanesulfonate,methyl benzenesulfonate, ethyl benzenesulfonate, propylbenzenesulfonate, phenyl methanesulfonate, phenyl ethanesulfonate,phenyl propanesulfonate, methyl benzylsulfonate, ethyl benzylsulfonate,propyl benzylsulfonate, benzyl methanesulfonate, benzyl ethanesulfonateand benzyl propanesulfonate; cyclic sulfonic acid esters such as1,3-propanesultone, 1,4-butanesultone, 3-phenyl-1,3-propanesultone and4-phenyl-1,4-butanesultone; and halides of such linear and cyclicsulfonic acid esters.

Specific examples of the compound having “A” as represented by theformula (5) include chain sulfuric acid esters such as dimethyl sulfate,diethyl sulfate, ethyl methyl sulfate, methyl propyl sulfate, ethylpropyl sulfate, methyl phenyl sulfate, ethyl phenyl sulfate, phenylpropyl sulfate, benzyl methyl sulfate and benzyl ethyl sulfate; cyclicsulfuric acid esters such as ethylene glycol sulfuric ester,1,2-propanediol sulfuric ester, 1,3-propanediol sulfuric ester,1,2-butanediol sulfuric ester, 1,3-butanediol sulfuric ester,2,3-butanediol sulfuric ester, phenylethylene glycol sulfuric ester,methylphenylethylene glycol sulfuric ester and ethylphenylethyleneglycol sulfuric ester; and halides of such chain and cyclic sulfuricacid esters.

The compound represented by the formula (1) maybe used singly, or two ormore of such compounds may be used in combination in the electrolytecomposition.

Compounds represented by the formula (1) are exemplified as ethylenesulfite, dimethyl sulfite, sulfolane, sulfolane and 1,3-propane sultone.

The amount of the compound represented by the formula (1) contained inthe organic solvent of the nonaqueous electrolyte solution is preferablywithin a range of 0.05 to 100 vol %, 0.05 to 60 vol %, 0.1 to 15 vol %,or 0.5 to 2 vol %. Alternatively, the additive is with a range of 0.1 to5 wt %, 1-3 wt %, or 1-1.5 wt %. Some of the compounds represented bythe formula (1) are solid in the room temperature, such compoundspreferably being used at an amount equal to or lower than the saturationsolubility for the organic solvent used, and more preferably at 60 wt %of the saturation solubility or lower, and still more preferably at 30wt % or lower. Thus, the additive remains dissolved and in solution inthe organic solvent over an anticipated use temperature range, such ase.g., between −30° C. and +70° C.

Content of vinylene carbonate in the mixed solvent for the nonaqueouselectrolytic solution is preferably from 0.2 to 8 vol %, or from 0.5 to3 vol %, or 0.5 to 2 vol %.

Additional organic solvents of the nonaqueous electrolytic solution mayalso be used, and examples of which include cyclic carbonates such asethylene carbonate, propylene carbonate and butylene carbonate; chaincarbonates such as dimethyl carbonate, diethyl carbonate and ethylmethyl carbonate; cyclic esters such as γ-valerolactone; chain esterssuch as methyl acetate and methyl propionate; cyclic ethers such astetrahydrofuran, 2-methyl tetrahydrofuran and tetrahydropyran; chainethers such as dimethoxyethane and dimethoxymethane; cyclic phosphoricacid esters such as ethylene methyl phosphate and ethyl ethylenephosphate; chain phosphoric acid esters such as trimethyl phosphate andtriethyl phosphate; halides thereof; sulfur-containing organic solventsother than those represented by the formula (1) and by vinyl ethylenecarbonate (VEC) and fluoroethylenecarbonate (FEC), poly(ethylene glycol)diacrylate. These organic solvents may be used singly, or two or more ofsuch solvents may be used in combination.

Exemplary electrolyte compositions include the addition of 0.1-5 wt %ethylene sulfite, ethylene sulfite, dimethyl sulfite, sulfolane,sulfolene or 1,3-propane sultone to 0.2-8 vol %, vinylene carbonate to asolution containing 0.6-2 mol/l of a lithium salt in a mixture oforganic solvents, e.g., ethylene carbonate, propylene carbonate,ethylmethyl carbonate, diethyl carbonate. In some embodiments, 0.1-5 wt% ethylene sulfite and 0.2-8 vol % vinylene carbonate are added to a0.6-2 mol/l LiPF₆ solution in a mixture of 35 vol % ethylene carbonate,5 vol %, propylene carbonate, 50 vol % ethylmethyl carbonate, and 10 vol% diethyl carbonate. Some embodiments include the addition of 1-3 wt %ethylene sulfite and 0.5-3 vol %, vinylene carbonate to a 0.6-2 mol/lLiPF₆ solution in a mixture of 35 vol % ethylene carbonate, 5 vol %propylene carbonate, 50 vol %, ethylmethyl carbonate, and 10 vol %diethyl carbonate. In other embodiments, 1-1.5 wt % ethylene sulfite and0.5-2 vol % vinylene carbonate are added to a 0.6-2 mol/l LiPF₆ solutionin a mixture of 35 vol % ethylene carbonate, 5 vol % propylenecarbonate, 50 vol %, ethylmethyl carbonate, and 10 vol % diethylcarbonate.

Examples of the lithium salt used for the nonaqueous electrolyticsolution are inorganic lithium salts such as LiClO₄, LiPF₆, LiBF₄ andfluorine-containing organic lithium salts such as LiCF₃SO₃,LiN(CF₃SO₂)₂, LiN(CF₃CF₂SO₂)₂, LiN(CF₃SO₂) (C₄F₉SO₂) and LiC(CF₃SO₂)₃.These salts may be used singly or in combination of two or more. Molarconcentration of the lithium salt in the electrolytic solution ispreferably within a range from 0.5 to 2.0 mol/l.

In some embodiments, the cathode active material is a lithium transitionmetal oxoanion material selected from the group:

(a) a composition Li_(x)(M′_(1-a)M″_(a))_(y)(XO₄)_(z),Li_(x)(M′_(1-a)M″_(a))_(y)(OXO₄)_(z), orLi_(x)(M′_(1-a)M″_(a))_(y)(X₂O₇)_(z) having a conductivity at 27° C. ofat least about 10^(−S) S/cm, wherein M′ is a first-row transition metal,X is at least one of phosphorus, sulfur, arsenic, boron, aluminum,silicon, vanadium, molybdenum and tungsten, M″ is one or more Group IIA,IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal,0.0001<a≦0.1, and x, y, and z are greater than 0 and have values suchthat x, plus y(1-a) times the formal valence or valences of M′ plus yatimes the formal valence or valences of M″ is equal to z times theformal valence of the XO₄, X₂O₇ or OXO₄ group:

(b) a composition (Li_(1-a)M″_(a))_(x)M′_(y)(XO₄)_(z),(Li_(1-a)M″_(a))_(x)M′_(y)(XO₄)_(z), or(Li_(1-a)M″_(a))_(x)M′_(y)(X₂O₇)_(z), having a conductivity at 27° C. ofat least about 10⁻⁸ S/cm, wherein M is a first-row transition metal, Xis at least one of phosphorus, sulfur, arsenic, boron, aluminum,silicon, vanadium, molybdenum and tungsten, M″ any of a Group IIA, IIIA,IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal,0.0001<a≦0.1, and x, y, and z are greater than 0 and have values suchthat (1-a)x plus the quantity ax times the formal valence or valences ofM″ plus y times the formal valence or valences of M′ is equal to z timesthe formal valence of the XO₄, X₂O₇ or OXO₄ group; and

(c) a composition (Li_(b-a)M″_(a))_(x)M′_(y)(XO₄)_(z),(Li_(b-a)M″_(a))_(x)M′_(y)(OXO₄)_(z), or(Li_(b-a)M″_(a))_(x)M′_(y)(O₂D₇)_(z) having a conductivity at 27° C. ofat least about 10⁻⁸ S/cm, wherein M′ is a first-row transition metal, Xis at least one of phosphorus, sulfur, arsenic, boron, aluminum,silicon, vanadium, molybdenum and tungsten, M″ any of a Group IIA, IIIA,IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D isoxygen, 0.0001<a≦0.1, a≦b≦1, and x, y, and z are greater than 0 and havevalues such that, (b-a)x plus the quantity ax times the formal valenceor valences of M″ plus y times the formal valence or valences of M′ isequal to z times the formal valence of the XO₄, X₂O₇ or OXO₄ group.

In some embodiments, the cathode active material is a lithium transitionmetal phosphate compound having the formula (Li_(1-x)Z_(x))MPO₄, where Mis one or more of vanadium, chromium, manganese, iron, cobalt andnickel, Z is one or more of titanium, zirconium, niobium, aluminum,tantalum, tungsten or magnesium, and x ranges from 0 to 0.05 orLi_(1-x)MPO₄ wherein M is selected from the group consisting ofvanadium, chromium, manganese, iron, cobalt and nickel; and 0≦x≦1.

In certain embodiments, the cathode active material is a lithium metalphosphate, for example lithium iron phosphate.

In some embodiments the positive active material consists of powder orparticulates with a specific surface area of greater than 5 m²/g, 10m²/g, or greater than 15 m²/g, or greater than 20 m²/g, or even greaterthan 30 m²/g.

LiFeO₄, having the olivine structure and made in the form of very small,high specific surface area particles are exceptionally stable in theirdelithiated form even at elevated temperatures and in the presenceoxidizable organic solvents, e.g., electrolytes, thus enabling a saferLi-ion battery having a very high charge and discharge rate capability.In addition, the small-particle-size, high specific-surface-area LiFePO4material exhibits not only high thermal stability, low reactivity andhigh charge and discharge rate capability, but it also exhibitsexcellent retention of its lithium intercalation and deintercalationcapacity during many hundreds, or even thousands, of high-rate cycles.

The transition-metal doped LiFeO4 has a markedly smaller particle sizeand much larger specific surface area than previously known positiveactive materials, such as LiCoO2, LiNiO₂ or LiMn₂O₄ and, thus improvedtransport properties. While methods are known to produce thesetraditional positive active materials in the form of high specificsurface area powders, Li-ion battery batteries made from such materialshave inferior safety and stability characteristics due to a combinationof the high oxidation potential and low inherent thermal stability ofthese conventional materials in their partially or fully delithiatedform, such as that existing in a partially or fully charged Li-ionbattery.

Materials for the anode can include, carbonaceous materials capable ofoccluding and liberating lithium such as decomposition products obtainedby thermal decomposition of organic substances under a variety ofconditions, hard (non-graphitizable) carbon, artificial graphite andnatural graphite. Alternately, the materials for composing the negativeelectrode can include combinations of these carbonaceous materials incombination with silicon or silicon oxide. These materials may be usedsingly or in combination of two or more.

When the graphitic carbonaceous materials are used, it is preferable touse an artificial graphite made from soft (graphitizable) pitch ofvarious origins processed by high temperature annealing; purifiednatural graphite; or these graphites subjected to a variety of surfaceprocessings with, for example, pitch.

There is no restriction on the method of fabricating the negative orpositive electrode using the aforementioned active materials. Forexample, the electroactive material is mixed, as required, with abinder, conductive material, solvent, etc. to prepare a slurry, and theslurry is then coated on a substrate of a current collector, which isfollowed by drying to produce the electrode. Also, such electrodematerials may be subjected to roll forming or compression molding to befabricated into a sheet or pellet, respectively.

Types of the binder used for the fabrication of the electrode is notparticularly limited as far as it is stable to the solvent andelectrolytic solution used in the fabrication of the electrode. Examplesof the binder include resinous polymers such as polyethylene,polypropylene, polyethylene terephthalate, aromatic polyamide, andcellulose; rubbery polymers such as styrene-butadiene rubber, isoprenerubber, butadiene rubber, and ethylene-propylene rubber; thermoplasticelastomeric polymers such as styrene-butadiene-styrene block copolymerand its hydrogenated product, styrene-ethylene-butadiene-styrene blockcopolymer and its hydrogenated product, and styrene-isoprene-styreneblock copolymer and its hydrogenated product; flexible resinous polymerssuch as syndiotactic 1,2-polybutadiene, ethylene-vinyl acetatecopolymer, and propylene-α,-olefin (having 2 to 12 carbon atoms)copolymer; and fluorocarbon polymers such as polyvinylidene fluoride,polytetrafluoroethylene, and polytetrafluoroethylene-ethylene copolymer.

As the binder, one can also use a polymer composition having alkalimetal ion (lithium ion, in particular) conductivity. As such ionconductive polymer compositions, these may be used a composite systemmade of polymeric compound as combined with lithium salt or with analkali metal salt.

The negative electrode material and the binder may be mixed in variousmanners. For example, particles of both of them are mixed, or particlesof the negative electrode material are entangled with fibrous binder toform a mixture, or a layer of the binder is deposited on the surface ofthe particles. Mixing ratio of the binder to the particle of thenegative electrode material is preferably 0.1 to 30 wt % of the negativeelectrode material, and more preferably 0.5 to 10 wt %. Addition of thebinder at an amount exceeding 30 wt % tends to raise the internalresistance of the electrode, and less than 0.1 wt %, on the other hand,tends to weaken the adhesive strength between the current collector andnegative electrode material

In mixing the negative electrode material and the binder, a conductivematerial may be mixed jointly. Since the conductive material used is notrestricted in type, it may be a metal or a nonmetal. Examples of ametallic conductive material are those composed of metallic elementssuch as Cu or Ni. Examples of a nonmetallic conductive material arecarbon materials such as graphite, carbon black, acetylene black, andKetjen black. The mean particle diameter of the conductive material ispreferably 1 μm or less.

Mixing ratio of the conductive material is preferably 0.1 to 30 wt % ofthe negative electrode material, and more preferably 0.5 to 15 wt %. Bysetting the mixing ratio of the conductive material at 30 wt % or less,the charge and discharge capacity of the electrode per unit volume canbe made relatively high. When the mixing ratio of the conductivematerial is set at 0.1 wt % or more, a conduction path between theconductive materials can sufficiently be formed within the electrode.

The above-mentioned mixture containing at least the negative electrodematerial and the binder is applied onto the current collector foil. Theapplication of the mixture to the current collector can be performed bymeans known to those skilled in the art. When the mixture is a slurry,it can be applied onto the current collector by means of a die coater ora doctor blade. The mixture in a pasty form can be applied onto thecurrent collector by roller coating or the like. The mixture containinga solvent is dried to remove the solvent, whereby an electrode can beprepared.

The positive electrode containing the positive electroactive materialhas a specific surface area of the electrode measured using the nitrogenadsorption Brunauer-Emmett-Teller (BET) method after the densificationor calendaring step that is greater than 5 m²/g. A positive electrodecan have a thickness of less than 125 μm, e.g., between about 50 μm to125 μm, or between about 80 μm to 100 μm on each side of the currentcollector, and a pore volume fraction between about 40 and 70 vol. %.The active material is typically loaded at about 10-20 mg/cm², andtypically about 11-15 mg/cm².

The negative active material consists of powder or particulates with aspecific surface area measured using the nitrogen adsorptionBrunauer-Emmett-Teller (BET) method to be greater than about 2 m²/g, or4 m²/g, or even about 6 m²/g. The negative electrode can have athickness of less than 75 μm, e.g., between about 20 μm to 65 μm, orbetween about 40 μm to 55 μm on both sides of the current collector, anda pore volume fraction between about 20 and 40 vol. %. The activematerial is typically loaded at about 5-20 mg/cm², or about 4-5 mg/cm².

There is no particular restriction on the fabrication process of thepositive electrode, and a similar method for negative electrodedescribed above may be employed.

There is no specific limitation on the source material or morphology ofthe separator used for the cell of the present invention. The separatorserves to separate the negative electrode and the positive electrode soas to avoid their physical contact. The preferred separator has high ionpermeability and a low electrical resistance. Materials for theseparator are preferably selected from those excellent in stabilityagainst the electrolytic solution and in liquid holding properties. Forexample, nonwoven fabric or porous film made of polyolefins, such aspolyethylene and polypropylene, are used as the separator, into whichthe electrolytic solution is impregnated.

Methods for fabricating the nonaqueous electrolytic solution cell usingsuch nonaqueous electrolytic solution, negative electrode, positiveelectrode, outer container and separator, is of no specific limitation,and can properly be selected from those being generally employed. Thenonaqueous electrolytic solution cell of the present invention mayinclude, if necessary, a gasket, a sealing plate and a cell case besidessuch nonaqueous electrolytic solution, negative electrode, positiveelectrode, outer can or pouch material and separator.

In some embodiments, improvement with low temperature applications isobserved using the pouch instead of the can container.

The battery as described herein demonstrates advantageous propertiesover an extreme of temperatures in which a battery can be expected tooperate. For example the battery is capable of operation between −30° C.and +70° C. Lowered impedance of the battery is important in bothincreasing performance at lower temperatures and lengthening batterylife. This can be achieved via a combination of design parameters, e.g.selection of specific organic solvents in the electrolyte, increasingelectrode surface area and pore volume, as well as the use ofadvantageous battery containers.

In general, a thicker electrode layer (and higher active materialloading) provides greater total capacity for the battery. However,thicker layers also increase the electrode impedance. Contrary toconventional practice and in accordance to one or more embodiments, highcapacity, thick layers may be used in a low impedance (high rate) cell.Use of a high specific surface area active material, while maintainingadequate pore volume, provides the desired capacity without increasingimpedance to unacceptably high levels. For more information, see U.S.application Ser. No. 11/052,971, incorporated herein by reference.

In terms of battery containers, improvement with low temperatureapplications is observed using the pouch instead of the can container.When cold cranking a battery, for example to start an engine, one wantsto draw a large current. As lithium cells are more resistive at coldtemperatures, the high current generates heat in the battery. As thecell heats up, the viscosity of the electrolyte decreases, and theresulting lower battery impedance allows for even greater drawing ofcurrent. This process is called “self-heating.” As self-heating isimportant for enhanced low temperature performance, improved resultswere observed for batteries that use pouch cell containers as opposed tocylindrical (can) cells. This is due to the improved packing density andincreased heat insulation of pouch-based batteries. Can-type cellsrequire lower impedance at low temperatures to compensate for thedecreased efficiency of self-heating.

Selection of organic solvents in the electrolyte is also important inreducing impedance. In some embodiments, the electrolyte isadvantageously free of γ-butyrolactone. It is known in the art thatγ-butyrolactone can undergo reductive oxidation on the negativeelectrode when the battery is charging (see, e.g., Petibon et. Al,Journal of the Electrochemical Society, 160(1) A117-A124(2013)). Theresulting decomposition products cause clogging of the separator. Thisincreases the surface resistance of the negative electrode, e.g.increases impedance at the anode, leading to significant capacity losswith cycling.

Additionally, the use of the additive as represented by formula (1) inaddition to vinylene carbonate (VC) in organic electrolytes leads tostable, lower impedance lithium ion batteries. Without being bound byany specific theory, it appears that the additive lowers impedance byreacting with the anode to create a solid electrolyte interface (SEI)that is more ionically conductive than with an electrolyte without theadditive. In addition, VC is efficient at passivation of thecarbon-based anode during initial charging. VC prevents the additivefrom decomposing by making the SEI less soluble.

The SEI originates from the thermodynamic instability of graphite-basedanodes in an organic electrolytes. The first time a battery is charged(“formation”), the graphite reacts with the electrolyte. This forms aporous passivating layer (called a solid electrolyte interphase, or SEI)that actually protects the anode from further attacks, moderating thecharge rate and restricting current. This reaction also consumes littlelithium. At high temperatures or when the battery runs all the way downto zero charge (“deep cycling”), the SEI can partially dissolve into theelectrolyte. (At high temperatures, electrolytes also tend to decomposeand side reactions accelerate, potentially leading to thermal runaway.)When temperatures become lower, another protective layer will form, butthis will consume more lithium, leading to higher capacity losses. Thus,stability of the SEI at high temperatures, one benefit of the batterydescribed herein, is important in increasing the life of the battery.

However, if the SEI layer thickens too much, it actually becomes abarrier to the lithium ions, increasing impedance. That affects powerperformance which is important for electric vehicles.

One way to define cell impedance is to measure area specific impedance.Impedance values can be determined for the total cell or for specificjunctions, such as the anode or the cathode. Area specific impedance(ASI) is the impedance of a device normalized with respect to surfacearea and is defined as the impedance measured at 1 kHz (Ω), using an LCZmeter or frequency response analyzer, multiplied by the surface area ofopposing electrodes (cm²). This measurement is typically performed byapplying a small (e.g., 5 mV) sinusoidal voltage to the cell andmeasuring the resulting current response. The resulting response can bedescribed by in-phase and out-of-phase components. The in-phase (real orresistive) component of the impedance at 1 kHz is then multiplied by thesurface area of opposing electrodes (cm²) to give the area specificimpedance. Area specific impedance can be used to determine theimpedance at the anode or at the cathode.

In one aspect, the rechargeable battery is used in a battery system thatoperates as a microhybrid battery. Micro-hybrid batteries (or vehicleswith start-stop feature) enable the vehicle's internal combustion engineto stop running when the vehicle is stationary, such as at a trafficlight, saving fuel by up to 10% above conventional vehicles. When thedriver releases the brake to press the gas pedal, the engine quicklystarts again before the vehicle moves forward. While the development ofearly generation micro-hybrids focused on smooth engine restarts, nextgeneration systems are looking to recover braking energy as a path toeven greater fuel economy. Existing lead acid micro-hybrid batterytechnology introduces some design constraints because it can't becharged very quickly and most of the vehicle's braking energy is stilllost. Batteries with lithium-ion chemistries have a much higher rate ofcharge acceptance and therefore are positioned to support nextgeneration micro-hybrid systems with higher rates of fuel economyimprovement.

Microhybrid batteries can be used as starter batteries for car engines.Their proximity to the engine and location under the hood often does notallow space for bulky thermal management circuitry. Thus, the batteryneeds to be able to start the engine at cold, ambient temperatures, downto −30° C., without heat input. Additionally, the battery needs to beable to work for extended periods of time under the temperatures of aworking car engine (up to 75° C.) without external cooling. Traditionallithium ion batteries suffer from high impedance at low temperatures,which reduces their ability to start an engine. Additionally, designsfor increasing power at low temperature in lithium ion batteries oftenresult in short life at high temperature. Although lead acid batterieshave improved cold cranking capabilities, they suffer from shortlifespans as opposed to lithium ion batteries for start-stopapplications.

The nonaqueous electrolytic solution cell of the present disclosure isexcellent in low temperature characteristics and long-term stability,and further in cycle characteristics when used in a microhybrid batterysystem. This technology enhances the success of lithium ion batteries inmicro-hybrids, especially as starter batteries, because it boosts thecold power of the battery allowing it to start the vehicle's engine evenin worst case cold temperatures. Additionally, the extended life of thebattery at high temperature environments is significant because a commonpackage location for starter batteries is the engine compartment wheretemperatures are usually higher than ambient during vehicle operation.

FIG. 1 shows a lithium-ion 12V microhybrid engine start battery 100,according to one embodiment. It is made up of a prismatic battery module110 with sixteen 20 Ah cells 120 with modified electrolyte compositionin a 4s4p configuration for 80 Ah of total capacity (1.06 kWh). Thebattery module is housed in standard automotive starter batteryenclosure 130 (EN50342-2, LN4) with outer dimensions of 175×190×315 mm.The unit includes an onboard battery management system with MOSFETs 140to control the connection to the vehicle system. The management systemincludes a cut-off switch comprising a plurality of MOSFETs for makingand breaking a conductive path between the plurality of rechargeablebatteries and an external contact. The management system also includes amicroprocessor which is configured through firmware to perform functionssuch as providing input protection and control of charging,enable/disable circuitry to decrease current consumption, and senseindividual battery cell temperature and voltage. The batterycommunicates via LIN bus protocol 150 with an operating voltage of 9 to14.4V to support a standard 12V vehicle powernet. FIG. 1 inset shows aphotograph of the battery. In some embodiments, the microhybrid batteryhas reduced thermal management circuitry. Further detail is provided inU.S. application Ser. No. 13/513665, incorporated herein by reference.

The present invention will be explained in more detail with reference tothe following examples. Materials, amounts of uses, ratios, operationsand so forth described hereinafter are properly be altered withoutdeparting from the spirit of the present invention. The scope of thepresent invention, therefore, is not limited to specific examplesdescribed below. The invention is applicable to any form of battery,e.g. prismatic, button-cell, can, etc.

EXAMPLE 1 Control Electrolyte Formulation

The control electrolyte formulation consisted of 1M LiPF₆ inEC:PC:EMC:DEC=35:5:50:10 v/v %+VC 2 wt %. “EC” denotes ethylenecarbonate; “PC” denotes propylene carbonate; “EMC” denotes ethylmethylcarbonate; “DEC” denotes diethyl carbonate; and “VC”′ denotes vinylenecarbonate.

EXAMPLE 2 ES Only Electrolyte Formulation

This electrolyte formulation consisted of 1M LiPF₆ inEC:PC:EMC:DEC=35:5:50:10 v/v %+ES 1 wt %. Here, “ES” denotes ethylenesulfite. The addition of ES lowers impedance by reacting with the anodeto create a solid electrolyte interface (SEI) that is more ionicallyconductive than with the control electrolyte above. However, a batterywith this electrolyte (with ES additive only) cannot be charged duringformation because the SEI is unstable and generates a lot of gas duringdecomposition.

This effect is shown in FIG. 2 where a carbon-based anode versus lithiumhalf-cell is charged for the first time (“formation” of the SEI curve).A slurry composed of 92 wt.-% artificial graphite, 4 wt.-% conductivecarbon additive and 4 wt.-% poly(vinylidene fluoride) (PVDF) binder inN-methylpyrrolidinone (NMP) was coated on a 10 μm thick copper foil,dried in the oven and calendered to form the anode.

The dip in voltage seen in FIG. 2 signifies the formation of theelectrolyte. However, the voltage after the dip does not reach 0V (whichwould be the case if the graphite was fully lithiated), indicating acontinuous decomposition of the electrolyte and lack of effective SEIformation. (see, e.g., Abe et al., Electrochimia Acta 49(26), 4613-4622(2004)).

EXAMPLE 3 Modified Electrolyte Formulation (ES+VC)

This “modified” electrolyte formulation consisted of 1M LiPF₆ inEC:PC:EMC:DEC=35:5:50:10 v/v %+VC 2 wt %+ES 1 wt %. FIG. 3 shows a plotof the formation curves of secondary cells with electrolyte compositionsfrom Example 2 (“ES only”) and Example 3 (“ES+VC”, “modified”). Theapplied current steps are shown as well. Both cells use the anode ofExample 2. A slurry composed of 92 wt.-% LiFePO₄, 4 wt.-% conductivecarbon additive and 4 wt.-% poly(vinylidene fluoride) (PVDF) binder inN-methylpyrrolidinone (NMP) was coated on a 20 μm thick aluminum foil,dried in the oven and calendered to form the cathodes for both cells.Prismatic cells using the cathode, anode, and a polyolefin microporousseparator were assembled with the electrolyte as known in the art.

As seen in FIG. 3, the addition of VC along with ES lowers batteryimpedance and aids in the formation of a stable SEI layer. The voltagedips seen in curve for “ES only” are characteristic of electrolytedecomposition and gassing. The monotonic voltage increase of the “ES+VC”curve indicates the formation of a stable SEI layer.

The use of ES as co-additive in addition to VC in organic electrolytesenables the proper formation of the SEI in a lithium ion battery andleads to lower impedance batteries.

EXAMPLE 4 Low Temperature Behavior

The behavior of a secondary cell with and without (“control”) themodified electrolyte was compared to absorbent glass mat (AGM) lead acidbattery at low temperatures. The modified electrolyte cell is describedin Example 3 (ES+VC). The “control” cell is the same as that of themodified cell, except the electrolyte composition does not contain ES orVC.

The results for cold cranking for 10 seconds at 7V are shown in FIGS. 4A(for 60 Ah cells) and 3B (for 80 Ah batteries). The difference inperformance reflects the improvements achieved using the modifiedelectrolyte as described herein.

As seen from these plots, the cells with the modified electrolytecomposition show 20-30% increase of current that can be drawn overcontrol cells (between −20 and −15° C.), and the same cold crankproperties as the lead acid batteries (at −17° C.).

EXAMPLE 5 High Temperature Storage

The disclosed modified electrolyte cells (ES+VC of Example 3) alsodisplayed improved high temperature storage capabilities as compared tocontrol cells. As shown in FIGS. 5A and B, the modified electrolytecells had reduced capacity loss after high temperature storage (55° C.)as compared to control cells. In addition, as shown in FIGS. 6A and 6B,the modified electrolyte cells lost less power after high temperaturestorage (55° C.) than the control.

EXAMPLE 6 High Temperature Cycling

The modified electrolyte cells (ES+VC of Example 3) also displayedimproved performance during high temperature cycling over other leadingmicrohybrid lithium ion competitors, as shown in FIGS. 7A and 7B andFIGS. 8A and 8B at various temperatures (45-75° C.), cycle rates (1 C-10C) and cycle numbers (300-5000).

Additionally, the modified electrolyte cells (ES+VC of Example 3) hadlower impedance growth as compared to the “control” batteries at 60° C.,as shown in FIG. 9.

Applications

Given the improved low-temperature characteristics and long-termstability of the modified electrolyte cells as disclosed herein, anumber of different applications are contemplated.

The voltage characteristics of the present cells make them particularlywell suited to 12-volt battery replacements. This is particularly truewith lithium metal phosphate (preferably lithium iron phosphate) cellswhere 4 cells achieve about 12 volts.

In telecommunications, the modified electrolyte secondary cells canreplace lead acid batteries (that are used during power outages tomaintain service in cell towers), which tend to degrade quickly at hightemperature.

In transportation, with increased fuel economy needs, more electricalloads are put on the battery rather than the engine. This is especiallytrue in micro-hybrid cars, trucks and buses that use “stop-and-start”technology, shutting off the engine when the driver slows the vehicledown or stops it. The modified electrolyte cell can enhance engine startwith improved cold crank performance, while extending life at hightemperature storage, more than twice the life of lead acid batteries inmicro-hybrid applications. The extended temperature performance alsolowers weight and cost of the battery by reducing or eliminating heatmanagement circuitry that is typically used in extreme temperatureconditions.

The reduced cost and weight of the battery is also useful for defenseapplications which require wide operating temperatures, for groundvehicles, space and satellite applications, aircrafts, and man-portablepersonal devices.

The foregoing discussion should be understood as illustrative and shouldnot be considered to be limiting in any sense. While the inventions havebeen particularly shown and described with references to preferredembodiments thereof, it will be understood by those skilled in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the inventions as defined by theclaims.

The corresponding structures, materials, acts and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or acts for performing the functions incombination with other claimed elements as specifically claimed.

1. A rechargeable battery comprising: a carbon-containing negative electrode capable of intercalating and liberating lithium, a positive electrode comprising a lithium transition metal oxoanion electroactive material, a separator; and a nonaqueous electrolyte solution comprising a lithium salt and at least one organic solvent, wherein the nonaqueous electrolytic solution is free of γ-butyrolactone and the organic solvent comprises vinylene carbonate, the at least one additive represented by the formula (1): R₁-A-R₂   (1) in which, R₁ and R₂ independently represent an alkyl group which may be substituted with an aryl group or halogen atom; an aryl group which may be substituted with an alkyl group or halogen atom; or may be taken together to form, together with -A-, a cyclic structure which may contain an unsaturated bond, where “A” is represented by a formula selected from the group consisting of


2. The rechargeable battery of claim 1 wherein the electrolytic solution contains 0.1 to 5 weight % of the compound represented by formula (1).
 3. The rechargeable battery of claim 1 wherein the electrolytic solution contains 1 to 3 weight % of the compound represented by formula (1).
 4. The rechargeable battery of claim 1 wherein the electrolytic solution contains 1 to 1.5 weight % of the compound represented by formula (1).
 5. The rechargeable battery of claim 1 wherein the electrolytic solution contains 0.2 to 8 vol % vinylene carbonate.
 6. The rechargeable battery of claim 1 wherein the electrolytic solution contains 0.5 to 3 vol % vinylene carbonate.
 7. The rechargeable battery of claim 1 wherein the electrolytic solution contains 0.5 to 2 vol % vinylene carbonate.
 8. The rechargeable battery of claim 1 wherein the compound represented by formula (1) comprises ethylene sulfite.
 9. The rechargeable battery of claim 1 where said negative electrode comprises carbonaceous materials.
 10. The rechargeable battery of claim 9 where said negative electrode comprises non-graphitizable carbon, artificial graphite, or natural graphite combinations of carbonaceous materials with silicon or silicon oxide.
 11. The rechargeable battery of claim 1, wherein the lithium transition metal oxoanion material is selected from the group consisting of: a composition Li_(x)(M′_(1-a)M″_(a))_(y)(XO₄)_(z), Li_(x)(M′_(1-a)M″_(a))_(y)(OXO₄)_(z), or Li_(x)(M′_(1-a)M″_(a))_(y)(X₂O₇)_(z) having a conductivity at 27° C. of at least about 10⁻⁸ S/cm, wherein M′ is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, boron, aluminum, silicon, vanadium, molybdenum and tungsten, M″ is one or more Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, 0.0001<a≦0.1, and x, y, and z are greater than 0 and have values such that x, plus y(1-a) times the formal valence or valences of M′ plus ya times the formal valence or valences of M″ is equal to z times the formal valence of the XO₄, X₂O₇ or OXO₄ group; a composition (Li_(1-a)M″_(a))_(x)M′_(y)(XO₄)_(z), (Li_(1-a)M″_(a))_(x)M′_(y)(OXO₄)_(z), or (Li_(1-a)M″_(a))_(x)M′_(y)(X₂O₇)_(z), having a conductivity at 27° C. of at least about 10⁻⁸ S/cm, wherein M is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, boron, aluminum, silicon, vanadium, molybdenum and tungsten, M″ any of a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, 0.0001<a≦0.1, and x, y, and z are greater than 0 and have values such that (1-a)x plus the quantity ax times the formal valence or valences of M″ plus y times the formal valence or valences of M′ is equal to z times the formal valence of the XO₄, X₂O₇ or OXO₄ group; and a composition (Li_(b-a)M″_(a))_(x)M′_(y)(XO₄)_(z), (Li_(b-a)M″_(a))_(x)M′_(y)(OXO₄)_(z), or (Li_(b-a)M″_(a))_(x)M′_(y)(O₂D₇)_(z), having a conductivity at 27° C. of at least about 10⁻⁸ S/cm, wherein M′ is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, boron, aluminum, silicon, vanadium, molybdenum and tungsten, M″ any of a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D is oxygen, 0.0001 0.0001<a≦0.1, a≦b≦1 and x, y, and z are greater than 0 and have values such that, (b-a)x plus the quantity ax times the formal valence or valences of M″ plus y times the formal valence or valences of M′ is equal to z times the formal valence of the XO₄, X₂O₇ or OXO₄ group.
 12. The rechargeable battery of claim 1, wherein the lithium transition metal oxoanion material is a lithium transition metal phosphate compound having the formula selected from the group consisting of: (a) (Li_(1-x)Z_(x))MPO₄, where M is one or more of vanadium, chromium, manganese, iron, cobalt and nickel, Z is one or more of titanium, zirconium, niobium, aluminum, tantalum, tungsten or magnesium, and x ranges from 0 to 0.05; and (b) Li_(1-x)MPO₄, wherein M is selected from the group consisting of vanadium, chromium, manganese, iron, cobalt and nickel; and 0≦x≦1.
 13. The rechargeable battery of claim 1 where said positive electrode has a specific surface area of at least 5 m²/g.
 14. The rechargeable battery of claim 1 where the positive electrode comprises olivinic lithium iron phosphate, optionally containing one or more additional metals.
 15. The rechargeable battery of claim 1, wherein the battery comprises a sold electrolyte interface (SEI) layer at the anode and the SEI layer comprises a reaction product that is the result of a reaction of the carbon-containing negative electrode and the additive represented by the formula (1).
 16. The rechargeable battery of claim 15, wherein the area specific impedance at the anode is less than the impedance at an anode in a cell lacking the additive represented by the formula (1).
 17. The rechargeable battery of claim 1, wherein the molar concentration of the lithium salt is between 0.5 and 2.0 mol/l.
 18. The rechargeable battery of claim 1, wherein the lithium salt is selected from the group consisting of LiClO₄, LiPF₆, LiBF₄, LiCF₃SO₃, LiN(CF₃SO₂)₂, LiN(CF₃CF₂SO₂)₂, LiN(CF₃SO₂)(C₄F₉SO₂) and LiC(CF₃SO₂)₃.
 19. The rechargeable battery of claim 1, wherein the electrolytic solution further comprises aprotic solvents.
 20. The rechargeable battery of claim 19, wherein the solvent comprises at least one of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, γ-valerolactone, methyl acetate, methyl propionate, tetrahydrofuran, 2-methyl tetrahydrofuran, tetrahydropyran, dimethoxyethane, dimethoxymethane, ethylene methyl phosphate, ethyl ethylene phosphate, trimethyl phosphate, triethyl phosphate, halides thereof, vinyl ethylene carbonate and fluoroethylenecarbonate, poly(ethylene glycol), diacrylate, and combinations thereof.
 21. The rechargeable battery of claim 1, wherein the electrolytic solution comprises a mixture of ethylene carbonate, propylene carbonate, ethylmethyl carbonate, and diethyl carbonate.
 22. The rechargeable battery of claim 1, where the battery is contained within a pouch.
 23. A battery system, comprising a plurality of rechargeable batteries, wherein the rechargeable battery comprises the rechargeable battery of claim
 1. 24. The battery system of claim 23, wherein the plurality of rechargeable batteries are configured to provide an operating voltage of about 9 to 14.4 volts.
 25. The battery system of claim 23, wherein the battery is capable of operating within −30° C. to +70° C. without battery management circuitry.
 26. The battery system of claim 23, comprising 4 to 16 cells with cathodes comprising lithium iron phosphate.
 27. A microhybrid battery comprising: a battery housing; a plurality of rechargeable batteries within the battery housing, wherein the rechargeable battery comprises the rechargeable battery of claim 1; and a cut-off switch for making and breaking a conductive path between the plurality of rechargeable batteries and an external contact.
 28. The microhybrid battery of claim 27, wherein the plurality of rechargeable batteries are configured to provide an operating voltage of about 9 to 14.4 volts.
 29. The microhybrid battery of claim 27, wherein the battery is capable of operating within −30° C. to +70° C. without battery management circuitry.
 30. The micro hybrid battery of claim 27, wherein the battery capacity decreases less than 10% after 300 charge-discharge cycles at 75° C. with 100% depth of discharge and at least 1 C charge rate.
 31. The microhybrid battery of claim 27, wherein the battery can draw at least 20% more current at −30° C. than a battery comprising rechargeable batteries lacking the additive represented by formula (1).
 32. A nonaqueous electrolyte solution comprising: a lithium salt; and at least one organic solvent, wherein the nonaqueous electrolytic solution is free of γ-butyrolactone and the organic solvent comprises vinylene carbonate, and at least one additive represented by the formula (1): R₁-A-R₂ in which, R1 and R2 independently represent an alkyl group which may be substituted with an aryl group or halogen atom; an aryl group which may be substituted with an alkyl group or halogen atom; or may be taken together to form, together with -A-, a cyclic structure which may contain an unsaturated bond, where “A” is represented by a formula selected from the group consisting of


33. The nonaqueous electrolyte solution of claim 32 wherein the electrolytic solution contains 0.1 to 5 weight % of the compound represented by formula (1).
 34. The nonaqueous electrolyte solution of claim 32 wherein the electrolytic solution contains 0.1 to 3 weight % of the compound represented by formula (1).
 35. The nonaqueous electrolyte solution of claim 32 wherein the electrolytic solution contains 1 to 1.5 weight % of the compound represented by formula (1).
 36. The nonaqueous electrolyte solution of claim 32 wherein the electrolytic solution contains 0.2 to 8 vol % of vinylene carbonate.
 37. The nonaqueous electrolyte solution of claim 32 wherein the electrolytic solution contains 0.5 to 3 vol % of vinylene carbonate.
 38. The nonaqueous electrolyte solution of claim 32 wherein the electrolytic solution contains 0.5 to 2 vol % of vinylene carbonate.
 39. The nonaqueous electrolyte solution of claim 32 wherein the compound represented by formula (1) comprises ethylene sulfite.
 40. The nonaqueous electrolyte solution of claim 32, wherein the electrolytic solution further comprises aprotic solvents.
 41. The rechargeable battery of claim 40, wherein the solvent comprises at least one of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, γ-valerolactone, methyl acetate, methyl propionate, tetrahydrofuran, 2-methyl tetrahydrofuran, tetrahydropyran, dimethoxyethane, dimethoxymethane, ethylene methyl phosphate, ethyl ethylene phosphate, trimethyl phosphate, triethyl phosphate, halides thereof, vinyl ethylene carbonate and fluoroethylenecarbonate, poly(ethylene glycol), diacrylate, and combinations thereof.
 42. The nonaqueous electrolyte solution of claim 32, wherein the electrolytic solution comprises a mixture of ethylene carbonate, propylene carbonate, ethylmethyl carbonate, and diethyl carbonate. 